SALIENCE DISTANCE TRANSFORM===========================The distance transform (DT) labels each pixel with the distance to the closestfeature pixel. We have extended this with the salience distance transform(Salience DT) by incorporating additional information reflecting the salienceof the feature pixels. Full details are given in:    P.L. Rosin & G.A.W. West,    "Salience distance transforms",    CVGIP: Graphical Models and Image Processing,    vol 57, no. 6, pp. 483-521, 1995.FORMATS=======Images are expected in PGM image format. The extracted edges are stored in a simple ASCII format. Each file startswith "pixel". Each connected chain of edge pixels is preceded by "list: ID",where ID is a unique integer for each edge chain, and is terminated by "-1 0",except for the last list which is terminated by "-1 -1". Between the listheader and terminator the co-ordinates of each pixel are given.COMPILING AND RUNNING THE PROGRAMS================================== Just type make to compile the programsThe following programs are included:    chamfer34_s.c      the standard chamfer34 distance transform    chamfer_sdt1.c     Salience DT incorporating edge strength    chamfer_sdt2.c     Salience DT incorporating edge strength and curve length    chamfer_sdt3.c     Salience DT incorporating edge strength, curve length,                       and clutterness    linknew.c          utility to extract curves from edge mapExamples:To run the standard DT you need a binary image. For instance, youcould threshold the edge map of lena (program not supplied) so that edgesare black (0), and then:    % chamfer34_s -i lena.threshold -o lena.dtTo run the Salience DT on the edge map of lena, incorporating edge strength:    % chamfer_sdt1 -e lena.edge -o lena.sdt1To run chamfer_sdt2 and chamfer_sdt3 you need to extract the edges as curvesusing linknew:    % linknew -i lena.edge -o lena.pixThen, to run the Salience DT on the edge map of lena, incorporating edgestrength and curve length:    % chamfer_sdt2 -e lena.edge -o lena.sdt2 -p lena.pixOr, to run the Salience DT on the edge map of lena, incorporating edge, curvelength, and clutterness:    % chamfer_sdt3 -e lena.edge -o lena.sdt3 -p lena.pix+-------------------------------------------------------------------+|Dr. Paul Rosin                                                     ||Department of Computer Science    email:   Paul.Rosin@cs.cf.ac.uk  ||Cardiff University                tel/fax: +44 (0)29 2087 5585/4598||Queen's Buildings, Newport Road, PO Box 916, Cardiff CF24 3XF, UK  ||WWW: http://www.cs.cf.ac.uk/User/Paul.Rosin/                       |+-------------------------------------------------------------------+